Potential Modern Alternative Designs for Caries Clinical Trials (CCTs) and How These can be Validated against the Conventional Model

The main reasons that industry runs caries clinical trials (CCTs) are to provide proof of efficacy and to collect in vivo safety data on new products. In recent years, predominantly due to declining caries levels and the use of positive controls, the cost of performing these CCTs has escalated. It is now reaching the stage where it is becoming commercially prohibitive to conduct new studies. This is likely to stifle innovation of new anticaries products, and we now need new, more discriminatory, faster, and less expensive study designs. There are many ways in which the design of CCTs may be changed, such as improving diagnostic efficiency, improving data handling/statistical modeling, and using high-risk populations. However, it is paramount that the overriding principle behind CCT design validation must be that the results/conclusions from any new design are in line with those shown previously by ‘conventional’ CCTs, to ensure the maintenance of standards for both efficacy and safety. It is suggested that the validation of any new trial design must involve comparisons with regimens previously shown in conventional CCTs to have different anticaries efficacies. For example, since several clinical trials have shown convincing evidence for a monotonic dose response for fluoride at least up to levels of 2500 ppm F, one could choose two products, differing solely in their fluoride level. One aim for this workshop is to identify and agree on validation principles for new clinical trial designs. This will facilitate general international acceptance of novel smaller/faster CCTs designs both now and in the future. We recognize that any new design must not compromise the standard of proof of either efficacy or safety. In addition, any principles will need to take account of current understanding of the caries process, while recognizing the need for change to match future developments in cariology. Finally, the mechanism of action of the test product must be considered, in assessments of the acceptability of novel designs, if this differs markedly from the regimens used to validate the design.

Clinical trial design in systemic lupus erythematosus: lessons learned and future directions

Designing successful randomized controlled trials (RCTs) in systemic lupus erythematosus (SLE) poses many challenges. It remains difficult to correlate alterations in biologic markers with clinical outcome, especially when signs and symptoms are intermittent and broadly variable between patients. Disease activity indices were not designed specifically as outcome measures in RCTs, as they were developed in the context of longitudinal observational studies. Although all disease activity indices have been validatedagainsteach other and demonstratedto show change, organ system manifestations are variably weighted; fatigue and autoantibodytiters are scored in some and not in others. Due to the variability of the underlying disease course an assessment of disease activity may most accurately be portrayed as change over time, such as an area under the curve analysis. Another lesson learned is that ’responder indices’ proposed in the absence of prospective validation in RCTs do not function well. The argument can always be made that any response criteria will work if the treatment is effective;but without the precedent of a product specifically approved for use in SLE, this is hard to prove. The ACR/Systemic Lupus International Cooperating Clinics (SLICC) damage index was designed to score irreversible manifestations of disease or consequences of its treatment, provided they had been present for at least six months. The damage index may best be utilized to stratify patients or balance randomization at baseline. It may also be incorporated into an endpoint analysis, to ensure that treatment or disease associated deterioration in organ system function (that may be overlooked in scoring disease activity alone) has not occurred. Patient cohort data have demonstrated that the medical outcomes survey short form-36 (SF-36) reflected the effects of SLE better than other patient reported measures. Worsening SF-36 domain scores best correlate with higher disease activity, increased glucocorticoid doses and use of cytotoxic agents. It has been shown sensitive to change in RCTs and observationalcohorts, and reflects the impact of treatment with high dose glucocorticoids and immunosuppressiveagents, as well as end stage renal disease. There is now a body of data derived from RCTs in SLE. Albeit limited, yet to result in an approved therapy, evidence is accumulating that indicate ’early markers’ of response can be defined which may correlate with longer term clinical outcomes. This should inform us in our ongoing efforts to clinically test a broad variety of promising interventions.

Pediatric Cancer Research From Past Successes Through Collaboration to Future Transdisciplinary Research

Multidisciplinary collaboration in therapeutic research in childhood cancer has been responsible for enormous improvements in outcomes. Many of the improvements have resulted from large clinical trials carried out in multisite settings through the Children’s Oncology Group (COG) and its predecessors, the Children’s Cancer Group, the Pediatric Oncology Group, the National Wilms’ Tumor Study, and Intergroup Rhabdomyosarcoma Study Groups. Childhood acute lymphoblastic leukemia models the past success of 35 years of randomized clinical trials that resulted in survival rates of around 80%. However, more can be done to improve both survival rates and the quality of survival. Areas that can benefit from a transdisciplinary model of research are discussed, as well as challenges to this form of collaboration.

Patient-centric trials for therapeutic development in precision oncology

An enhanced understanding of the molecular pathology of disease gained from genomic studies is facilitating the development of treatments that target discrete molecular subclasses of tumours. Considerable associated challenges include how to advance and implement targeted drug-development strategies. Precision medicine centres on delivering the most appropriate therapy to a patient on the basis of clinical and molecular features of their disease. The development of therapeutic agents that target molecular mechanisms is driving innovation in clinical-trial strategies. Although progress has been made, modifications to existing core paradigms in oncology drug development will be required to realize fully the promise of precision medicine.

Novel methods and technologies for 21st-century clinical trials: a review

IMPORTANCE

New technologies are rapidly reshaping health care. However, their effect on drug development to date generally has been limited.

OBJECTIVES

To evaluate disease modeling and simulation, alternative study design, novel objective measures, virtual research visits, and enhanced participant engagement and to examine their potential effects as methods and tools on clinical trials.

EVIDENCE REVIEW

We conducted a systematic search of relevant terms on PubMed (disease modeling and clinical trials; adaptive design, clinical trials, and neurology; Internet, clinical trials, and neurology; and telemedicine, clinical trials, and neurology), references of previous publications, and our files. The search encompassed articles published from January 1, 2000, through November 30, 2014, and produced 7976 articles, of which 22 were determined to be relevant and are included in this review.

FINDINGS

Few of these new methods and technologies have been applied to neurology clinical trials. Clinical outcomes, including cognitive and stroke outcomes, increasingly are captured remotely. Other therapeutic areas have successfully implemented many of these tools and technologies, including web-enabled clinical trials.

CONCLUSIONS AND RELEVANCE

Increased use of new tools and approaches in future clinical trials can enhance the design, improve the assessment, and engage participants in the evaluation of novel therapies for neurologic disorders.

Clinical trials in progressive multiple sclerosis: lessons learned and future perspectives

Progressive multiple sclerosis is characterised clinically by the gradual accrual of disability independent of relapses and can occur with disease onset (primary progressive) or can be preceded by a relapsing disease course (secondary progressive). An effective disease-modifying treatment for progressive multiple sclerosis has not yet been identified, and so far the results of clinical trials have generally been disappointing. Ongoing advances in the knowledge of pathogenesis, in the identification of novel targets for neuroprotection, and in improved outcome measures could lead to effective treatments for progressive multiple sclerosis. In this Series paper, we summarise the lessons learned from completed clinical trials and perspectives from trials in progress in progressive multiple sclerosis. We review promising clinical, imaging, and biological markers, along with novel designs, for clinical trials. The use of more refined outcomes and truly neuroprotective drugs, coupled with more efficient trial design, has the capacity to deliver a new era of therapeutic discovery in this challenging area.

Regulatory activities to address the needs of older patients

At the Drug Information Association (DIA) 49th annual meeting, for the first time regulators (Dr Francesca Cerreta, Dr Robert Temple and Dr Yasuko Asahina) from the three International Conference on Harmonization (ICH) co-sponsor regions came together in a forum to discuss their perspective on how the aging population impacts on drug development and on the design of clinical trials. In 2010, the ICH E7 Guideline (Studies in support of Special Populations: Geriatrics) was revised with the addition of a Questions and Answers document to take into account the rapidly changing world demographics. Regulators from the three ICH regions (Europe, USA and Japan) discuss here how they foresee the application of this guideline, and the impact that this might have on new drug development and clinical trial design. This article aims to summarize the discussions at the session for the benefit of a wider audience.

Primary Prevention and Delay of Onset of AD/Dementia

Prevention in Alzheimer's disease and other dementias (AD/dementia) is defined on the basis of clinical states and their expressed symptoms. Primary prevention refers to delaying the development of the full-blown state of clinically expressed disease in normal individuals. Current primary prevention research is driven by evidence of AD/dementia protective factors that have emerged from epidemiological studies. The first randomized controlled trials (RCTs) of primary AD/dementia prevention have been designed to test the efficacy and safety of NSAIDs, hormonal therapy, antihypertensive drugs and antioxidants. The experience of these trials has indicated safety concerns as a key issue and highlighted significant design challenges in this type of research. These trials have required large sample sizes and unsustainable costs. There should be consideration given in future trials to enriching study samples with risk factors to increase progression rates to AD/dementia. Innovative strategies will also be needed to recruit and retain subjects given the long follow-up periods, modest perceived benefit and the potential for the risk-benefit ratio to change during the trial. It is foreseeable that regulatory authorities will be presented with primary prevention RCTs for approval and labelling, and that criteria to evaluate such evidence still need to be developed.

Clinical Trials in Parkinson's Disease Dementia and Dementia with Lewy Bodies

Parkinson's disease with dementia (PDD) and dementia with Lewy bodies (DLB) are pathological overlapping and important causes of dementia for which clinical trials are in their infancy. Cholinesterase inhibitors may be of benefit in DLB and PDD, as suggested by placebo-controlled clinical trials of rivastigmine and donepezil. The anti-psychotic agent clozapine has been of benefit in PD and PDD, but other agents, such as quetiapine, require adequate assessment. Barriers to trials include pathological overlap that can lead to inaccuracies in clinical diagnosis, unavailability of a consensus definition for PDD, unanswered questions regarding natural history and the paucity of validated outcome measures. Motor impairment must be considered in patients with PDD and DLB; conversely, cognitive impairment should be assessed in trials targeting motor impairment in advanced PD. Potential targets for treatment include onset of dementia, cognitive impairment, behavioral impairment, functional decline, falls, nursing home placement, mortality, quality of life and economic impact. Biomarkers including neuroimaging and cerebrospinal fluid markers are not currently established. At present PDD and DLB are distinct entities by definition. Future studies, including clinical trials and biomarker studies, will help to further define the clinical and therapeutic implications of this distinction.

Clinical trials in peripheral vascular disease: pipeline and trial designs: an evaluation of the ClinicalTrials.gov database

BACKGROUND

Tremendous advances have occurred in therapies for peripheral vascular disease (PVD); until recently, however, it has not been possible to examine the entire clinical trial portfolio of studies for the treatment of PVD (both arterial and venous disease).

METHODS AND RESULTS

We examined interventional trials registered in ClinicalTrials.gov from October 2007 through September 2010 (n=40,970) and identified 676 (1.7%) PVD trials (n=493 arterial only, n=170 venous only, n=13 both arterial and venous). Most arterial studies investigated lower-extremity peripheral artery disease and acute stroke (35% and 24%, respectively), whereas most venous studies examined deep vein thrombosis/pulmonary embolus prevention (42%) or venous ulceration (25%). A placebo-controlled trial design was used in 27% of the PVD trials, and 4% of the PVD trials excluded patients >65 years of age. Enrollment in at least 1 US site decreased from 51% of trials in 2007 to 41% in 2010. Compared with noncardiology disciplines, PVD trials were more likely to be double-blinded, to investigate the use of devices and procedures, and to have industry sponsorship and assumed funding source, and they were less likely to investigate drug and behavioral therapies. Geographic access to PVD clinical trials within the United States is limited to primarily large metropolitan areas.

CONCLUSIONS

PVD studies represent a small group of trials registered in ClinicalTrials.gov, despite the high prevalence of vascular disease in the general population. This low number, compounded by the decreasing number of PVD trials in the United States, is concerning and may limit the ability to inform current clinical practice of patients with PVD.

[Current situation in clinical trials with vaccines in the Czech Republic]

Clinical trials are an important part of clinical research. The conduction of clinical trials is strictly regulated and has to comply with an approved protocol. Local regulatory authorities, independent ethic committees, sponsors of clinical trials as well as the investigators are involved from the submission until the very end of the trial. All clinical trials performed in the Czech Republic have to be approved by the State Institute for Drug Control and by the Ethics Committee. The regulatory bodies and independent ethics committees evaluate and continuously supervise the justification and protocol of the clinical trial, quality of the investigational medicinal products and, primarily, the safety of the participants (patients and/or healthy volunteers) in clinical trials. In the Czech Republic there are many advanced clinical research centres, either located in private practices or within hospitals. The investigators are able to conduct a wide variety of clinical trials and recruit a high number of subjects for the trials, as well as to comply with the Good Clinical Practice guidelines and other regulatory requirements. The aim of this article is to summarise the current situation of clinical trials in the Czech Republic as well as the opportunities for getting involved in clinical trials and obligations arising for health professionals from such an involvement.

Justifying community benefit requirements in international research

It is widely agreed that foreign sponsors of research in low- and middle-income countries (LMICs) are morally required to ensure that their research benefits the broader host community. There is no agreement, however, about how much benefit or what type of benefit research sponsors must provide, nor is there agreement about what group of people is entitled to benefit. To settle these questions, it is necessary to examine why research sponsors have an obligation to benefit the broader host community, not only their subjects. Justifying this claim is not straightforward. There are three justifications for an obligation to benefit host communities that each apply to some research, but not to all. Each requires a different amount of benefit, and each requires benefit to be directed toward a different group. If research involves significant net risk to LMIC subjects, research must provide adequate benefit to people in LMICs to avoid an unjustified appeal to subjects' altruism. If research places significant burdens on public resources, research must provide fair compensation to the community whose public resources are burdened. If research is for profit, research sponsors must contribute adequately to the upkeep of public goods from which they benefit in order to avoid the wrong of free-riding, even if their use of these public goods is not burdensome.

A framework to link international clinical research to the promotion of justice in global health

How international research might contribute to justice in global health has not been substantively addressed by bioethics. Theories of justice from political philosophy establish obligations for parties from high-income countries owed to parties from low and middle-income countries. We have developed a new framework that is based on Jennifer Ruger's health capability paradigm to strengthen the link between international clinical research and justice in global health. The 'research for health justice' framework provides direction on three aspects of international clinical research: the research target, research capacity strengthening, and post-trial benefits. It identifies the obligations of justice owed by national governments, research funders, research sponsors, and investigators to trial participants and host communities. These obligations vary from those currently articulated in international research ethics guidelines. Ethical requirements of a different kind are needed if international clinical research is to advance global health equity.

Targets for future clinical trials in Huntington's disease: what's in the pipeline?

The known genetic cause of Huntington's disease (HD) has fueled considerable progress in understanding its pathobiology and the development of therapeutic approaches aimed at correcting specific changes linked to the causative mutation. Among the most promising is reducing expression of mutant huntingtin protein (mHTT) with RNA interference or antisense oligonucleotides; human trials are now being planned. Zinc-finger transcriptional repression is another innovative method to reduce mHTT expression. Modulation of mHTT phosphorylation, chaperone upregulation, and autophagy enhancement represent attempts to alter cellular homeostasis to favor removal of mHTT. Inhibition of histone deacetylases (HDACs) remains of interest; recent work affirms HDAC4 as a target but questions the assumed centrality of its catalytic activity in HD. Phosphodiesterase inhibition, aimed at restoring synaptic function, has progressed rapidly to human trials. Deranged cellular signaling provides several tractable targets, but specificity and complexity are challenges. Restoring neurotrophic support in HD remains a key potential therapeutic approach. with several approaches being pursued, including brain-derived neurotrophic factor (BDNF) mimesis through tyrosine receptor kinase B (TrkB) agonism and monoclonal antibodies. An increasing understanding of the role of glial cells in HD has led to several new therapeutic avenues, including kynurenine monooxygenase inhibition, immunomodulation by laquinimod, CB2 agonism, and others. The complex metabolic derangements in HD remain under study, but no clear therapeutic strategy has yet emerged. We conclude that many exciting therapeutics are progressing through the development pipeline, and combining a better understanding of HD biology in human patients, with concerted medicinal chemistry efforts, will be crucial for bringing about an era of effective therapies.